uninstalling modules should give you some hints. But I personally never uninstall modules (unless there is a big problem), and I install quite a few to look at and test out. They're generally small (disk space is cheap) and generally don't conflict with each other. On the very rare occasion I do uninstall a module - I do it by hand (IIRC I've only done that once over 8+ years).

When you say "by-hand"... the times I've checked, I haven't seen a "make uninstall" target for the modules I've installed. Is that common (to not have an uninstall target)? If so, how do you uninstall?

I generally install by CPAN but about 1/4 of the time tests will fail. I then revert to installing by hand to see what tests fail and if I'm concerned about them.

Ahhh... I see. Thank you.

But, when you say you "install by-hand", does that mean you go to where CPAN.pm downloaded the source files (umm... maybe somewhere in /root/.cpan?) and run "perl Makefile.PL..."? Or do you download a fresh archive?

There is the upgrade command from CPAN. But be careful. You need to watch modules you heavily depend on (like DBI and your DBD's, and DBIx::Class) for interface changes. I wouldn't use any kind of automation for this /me is paranoid

So, how exactly do you "upgrade by-hand" if you've already got the previous version installed? If I were going from using a 1.x to a 2.x, I'd want to make sure all the 1.x files were completely removed first, right?